Apparatus for protecting downhole instruments from torsional and lateral forces

ABSTRACT

In the representative embodiment of the invention disclosed herein, delicate instruments and electronic circuitry used for obtaining downhole measurements are mounted within an elongated housing which is removably disposed within a tubular well tool body and uniquely restrained from movement in response to impacts or vibrations which might otherwise damage or destroy the components. In this preferred arrangement, at least one set of angularly disposed transverse clamps is mounted on the housing and respectively arranged for being laterally extended against the internal wall of the tubular tool body in response to increased well bore pressure as the tool is lowered into a well bore. Although the clamps are normally retracted to enable the housing to be readily moved into and out of the tool body at the surface, the pressure-induced frictional restraint between the extended clamps and the body walls will reliably restrain the housing and its components from both lateral and torsional movements in response to impacts or vibrations of a potentiallydestructive magnitude.

United States Patent Cubberly, Jr.

[-4 1 Nov. 11, 1975 APPARATUS FOR PROTECTING DOWNHOLE INSTRUMENTS FROM Primary E.raminer-David H. Brown TORSION L AND LATERAL FORCES Attorney, Agent, or Fir/71Wi]lliam R. Sherman; [75] Inventor: Walter E. Cubberly, Jr., Houston, Stewart R Moore; Ernest Archambeau T ex [57 ABSTRACT [73] Asslgnee: gchlumbrgerNTech$ology In the representative embodiment of the invention disorporatlon ew closed herein, delicate instruments and electronic cir- [22] Filed: Nov. 1, 1974 cuitry used for obtaining downhole measurements are mounted within an elongated housing which is remov- [211 Appl' 520079 ably disposed within a tubular well tool body and uniquely restrained from movement in response to im- 52 us. Cl. 166/53; 166/212; 166/241 pacts 9r vibrations which might Otherwise damage or 51 1111. 0. E21B 23/04 destroy the components In this Preferred arrange- [58] Field of Search 340/18 NC, 18 CM, 18 L1); ment, at least one set of angularly disposed transverse 73/151; 166/53, 241 212; 175/232 clamps is mounted on the housing and respectively arranged for being laterally extended against the internal [56] Referen Cit d wall of the tubular tool body in response to increased UNITED STATES PATENTS well bore pressure as the tool is lowered into a well 7 380 570 7/1945 H 1 340/18 LD bore. Although the clamps are normally retracted to T 6 7 H1957 53: 175/737 X enable the housing to be readily moved into and out of E' 2/1959 Haines f the tool body at the surface, the pressure-induced fric- 3:283:824 11/1966 1160111566121. 1 I: 166/212 tional restraint between the extended Clamps and the 3.448,805 6/1969 Brown 166/212 y Walls Will reliably restrain the housing and its 3.528.500 9/1970 Brown 166/212 Components from both lateral and torsional move- 3.583 2l9 6/1971 Lunstroth 73/151 ments in response to impacts or vibrations of a poten- 3,588.804 6/1971 Fort 340/l8 LD tially-destructive magnitude. 3.603.391 9/1971 Yann 166/212 3.770.006 11/1973 Sexton et al. 340/18 NC x 13 ClalmS, 2 Drawing Figures US. Patent Nov. 11, 1975 v m x 1 V p E NCODER;

MEASURING DE VICE MEASURING DE VICE GENERATOR 79 APPARATUS FOR PROTECTING DOWNI-IOLE INSTRUMENTS FROM TORSIONAL AND LATERAL FORCES v Over the past 20 years or so various systems have been proposed for periodically transmitting measurements of one or more downhole conditions or formation characteristics to the surface during the drilling of a borehole with a rotary drill bit. However, there has heretofore been little or no commercial implementation of these proposed systems for various technical and economic factors. As a result, it was not until the great increase in drilling costs in recent years that such downhole measuring-while-drilling" systems have become commercially feasible. As shown in US. Pat. No. 3,827,294, for example, one of the more-promising measuring-while-drilling systems of current interest employs a downhole electronic-measuring and acousticsignaling assembly which is coaxially mounted within the drill string just above the drill bit and cooperatively arranged for producing encoded acoustic data signals which are successively transmitted through the circulating mud stream in the drill string to appropriate signal-decoding equipment at the surface.

Those skilled in the art will appreciate, of course, that these measuring systems necessarily require a considerable amount of downhole electronic circuitry for obtaining the desired sub-surface measurements and selectively operating the acoustic signaler for producing the encoded acoustic signals. It will also be recognized that space limitations as well as the severe borhole environmental conditions make it essential that the downhole electronic circuitry be sealingly enclosed in a smalldiameter tubular enclosure of substantial length. To facilitate the repair and maintenance of the downhole assembly, its various circuit components and electronic elements are typically mounted along a narrow, elongated metal strip or chassis which is removably encased within the tubular enclosure. The enclosure must, of course, be completely sealed to protect its contents from the drilling mud flowing through the tool body around the tubular enclosure.

It will be recognized, moreover, that the downhole assembly must also be capable of withstanding the extreme impacts and severe vibrations which are ordinarily imposed on the measuring tool during a typical drilling operation. By way of example, impact or vibrational forces in the order of 20 to 25 times gravity are known to occur frequently. It is also recognized that in addition to such extreme lateral and longitudinal impacts, a typical drill string is also subjected to significant torsional forces and vibrations which, for example, are erratically developed as the rotating drill bit is momentarily slowed or halted by an obstruction on the bottom of the borehole and then resumes rotation as the bit breaks or cuts away the obstruction.

Those skilled in the art will recognize, therefore, that these severe torsional shocks particularly represent a major problem in designing the downhole electronics package to withstand these continued shocks. The necessity to arrange the electronics in an elongated and relatively-slender assembly will, of course, make the assembly particularly susceptible to torsional forces unless it is securely anchored at spaced intervals along its length. Nevertheless, it is not practical to simply bolt the electronics housing to the tool body at numerous longitudinally-spaced positions since this will both unduly complicate the disassembly and assembly of the downhole unit as well as needlessly create numerous potential leakage paths into the tool body.

Accordingly, it is an object of the present invention to provide new and improved downhole measuringand-signaling systems that are cooperatively arranged for reliably withstanding severe torsional and lateral forces but which also have a minimum number of possible leakage paths as well as being readily easy to assemble and disassemble.

This and other objects of the present invention are attained by mounting at least one set of angularly-disposed transversely-oriented pressure-actuated clamps on an elongated instrumentation housing which is arranged to be longitudinally inserted into a tubular tool body with the clamps being normally retracted to facilitate the insertion and withdrawal of the instrumentation housing. By appropriately arranging the clamps to be selectively extended in response to increased well bore pressures as the tool is lowered into a well bore, the instrumentation housing will be frictionally retarded or restrained against transverse movement under extreme torsional or lateral forces without subsequently hampering its free removal from the tool body at the surface.

The novel features of the present invention are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may be best understood by way of the following description of exemplary apparatus employing the principles of the invention as illustrated in the accompanying drawings, in which:

FIG. 1 schematically illustrates a typical measuringwhile-drilling tool including new and improved apparatus incorporating the principles of the present invention; and

FIG. 2 shows a preferred embodiment of the present invention where an elongated instrumentation housing is cooperatively restrained against torsional or lateral movements in relation to the body of the well too] depicted in FIG. 1.

Turning now to FIG. 1, a new and improved well tool 10 arranged in accordance with the present invention is depicted coupled in a typical drill string 11 having a rotary drill bit 12 dependently coupled thereto for excavating a borehole 13 through various earth formations. As the drill string 11 is rotated by a typical drilling rig (not shown) at the surface, substantial volumes of drilling fluid or a so-called mud are continuously pumped downwardly through the tubular drill string and discharged from the drill bit 12 to cool the bit as well as to carry earth cuttings removed by the bit to the surface as the mud is returned upwardly along the borehole 13 exterior of the drill string to a storage pit or surface vessel (not shown) for subsequent recirculation by the mud pumps. It will be appreciated, therefore, that the circulating mud stream flowing through the drill string 11 serves as a transmission medium that is well suited for transmitting acoustic signals to the surface at the speed of sound in the particular drilling fluid.

As is typical, data-transmitting means 14 are arranged on the well tool 10 and include one or more typical formation-property or condition-responsive measuring devices, as shown generally at 15 and 16, respectively coupled to an appropriate measurement encoder 17 operatively arranged to produce a series of electrical coded data signals that are representative of the several measurements being obtained by the measuring devices. Although a self-contained battery power supply could be employed, as shown generally at 18 it is preferred to employ a multi-bladed turbine driving a generator 19 for utilizing the circulating mud stream as a motivating source to generate electric power for operation of the data-transmitting means 14. The datatransmitting means 14 further include an electric motor 20 which is coupled to the encoder l7 and, as shown for example in US. Pat. No. 3,764,970, operatively arranged to respond to its coded output signals for rotatively driving an acoustic signaler 21 to successively interrupt or obstruct the flow of the drilling fluid through the drill string 11. The resulting acoustic signals produced by the acoustic signaler 21 will betransmitted to the surface through the mud stream flowing within the drill string 11 as encoded representations or data signals indicative of the one or more downhole conditions or formation properties respectively sensed by the various measuring devices and 16. As these data signals are successively transmitted to the surface, they are detected and converted into meaningful indications or records by suitable acoustic signal detecting-and-recording apparatus (not shown) such as that disclosed, for example, in US. Pat. No. 3,555,504.

In light of the previous discussion, it will, of course, be appreciated that most of the components comprising the data-transmitting means 14 must necessarily be isolated from the drilling mud flowing through the well tool 10. Accordingly, in the preferred embodiment of the tool 10 depicted in FIG. 1, the data-transmitting means 14 are arranged generally as illustrated with the acoustic signaler 21 and the turbine-generator 19 being respectively mounted on the upper and lower ends of an elongated, tubular enclosure or fluid-tight housing 22 supported within the body 23 of the tool. As illustrated, the instrumentation housing 22 is coaxially aligned within the tool body 23 by means such as two or more longitudinally-spaced multi-armed centralizers or so-called spiders, as at 24-26, for cooperatively defining an annular fluid passage 27 around the housing sufficient to accommodate the downwardly-flowing drilling mud. To facilitate the servicing of the datatransmitting means 14, it is preferred that this entire assembly be dependently suspended from laterallydirected support pins, as at 28, which are threaded into the tool body to respectively couple their inwardlyprojecting ends to the several arms of the uppermost centralizer 24. Thus, to remove the data-transmitting means 14 from the tool body 23, it is necessary only to unthread the coupling pins 28 and pull the assembly including the turbine-generator 19, the signaler 21 and the elongated housing 22 out of the body.

To protect the assembly carrying the data-transmission means 14 from the extreme longitudinally-directed impacts which will be imposed on the tool 10 during a typical drilling operation, it is preferred to resiliently isolate the housing 22 from the tool body 23. Accordingly, as illustrated in FIG. 1, in the preferred embodiment of the tool 10 the uppermost centralizer 24 is cooperatively coupled to the instrumentation housing 22 by means of a thick sleeve 29 of an elastomeric or other appropriate shock-absorbing material which is tightly bonded to the centralizer and the housing. Thus, it will be appreciated that the elastomeric sleeve 29 will, for the large part, effectively isolate the data-transmission means 14 from longitudinally-directed impacts or vibrations which will ordinarily occur during a drilling operation.

A: rcviously discussed, however, it is not at all uncommon for the tool 10 to be also subjected to severe torsional forces or vibrations which can ultimately damage or destroy various components and delicate elements contained within the instrumentation housing 22. It will be appreciated, for example, that when the rotational speed of the toolbody 23 is suddenly reduced or increased as previously described, there will be corresponding rotationalinertial forces imposed on the instrumentation housing 22 as well as its contents. Torsional vibrations or shocks of this nature will, for the large part, be only minimally restrained or dampened by the shock-absorbing sleeve 29 on the upper centralizing spider 24. Those skilled in the art will also recognize that if the other centralizers 25 and 26 are simply fastened to the tool body 23 by pins, as at 28, each of these additional fasteners would represent an unwanted potential leakage path through the body wall as well as further complicate the installation and removal of the instrumentation housing 22 from the body.

Accordingly, to accomplish the objects of the present invention, one or more of the centralizers 25 and 26 are provided with pressure-actuated shock-dampening means which, in their preferred embodiment, are arranged on the instrumentation housing 22 as depicted generally at 30 in FIG. 2. As shown there, each of the shock-dampening means 30 preferably includes an outwardlymovable housing -clamping member 31 slidably mounted in a lateral bore 32 on one of the several arms or spacers, as at 33, of the centralizer, as at 25, and adapted for operation by pressure-responsive actuating means such as a piston-operated cam member 34 which is movably disposed in a closed-end piston chamber 35 in the spacer arm, with cooperatively-inclined camming surfaces 36 and 37 being arranged, on the two members for moving the clamping member into engagement with the inner wall of the tool body 23 when the tool 10 is operating in the borehole 13. It will, of course, be recognized that since the piston chamber 35 is always at a reduced or atmospheric pressure, the outward force imposed by the clamping member 31 against the inner wall of the tool body 23 will be directly related to the magnitude of the mud pressure in the fluid passage 27, the effective pressure-responsive area of the piston member 34, and the angular relationship between the camming surfaces 36 and 37. A typical biasing spring 38 is arranged in the piston chamber 35 for returning the piston member 34 to its normal position as the tool 10 is removed from the borehole 13.

In any event, those skilled in the art will appreciate that upon imposition of a significant pressure in the annular flow passage 27 around the instrumentation housing 22, the piston member 34 will urge downwardly into the piston member 35 for extending the laterallyoriented clamping member 31 into firm engagement with the adjacent wall portion of the tool body 23. If the centralizer 25 is provided with only the single clamping member 31, its extension will, of course, also serve to urge the opposite centralizer spacer (not shown in FIG. 2) against the opposite side of the tool body 23 so that the overall clamping force securing the instrumentation housing 22 to the body will be related to the motivating pressure applied to the single piston member 34. On the other hand, if one or more of the other spacers of the centralizer 25 are similarly equipped with clamping members and piston-operated c'am members as at 31 and 34, this overall clamping force will also be dependent upon the total number of clamping members and cam members and their respective design parameters.

In keeping with the objects of the present invention, therefore, it must be recognized that regardless of the number of clamping members and cam members, as at 31 and 34, employed in the centralizer or whether the centralizer 26 is similarly equipped with such pressure-responsive shock-dampening means, their overall net effect will be to firmly anchor the instrumentation housing 22 against rotation in relation to the tool body 23. The degree of restraint provided by these shockdampening means as at 30 will, of course, be functionally dcpendent upon the overall frictional forces developed between the tool body 23 and the outward faces of the one or more clamping members, as at 31, or any of the centralizing spacer arms which are not carrying such clamping members.

This, of course, means that the instrumentation hous ing 22 will be frictionally secured against turning in relation to the tool body 23 so long as the overall frictional forces imposed by the shock-dampening means 30 for holding the housing in place are at least equal to any torsional or rotational forces acting thereon which would otherwise cause the housing to turn in relation to the tool body. On the other hand, the shock-dampening means 30 will allow the instrumentation housing 22 to move in relation to the tool body 23 Whenever the forces tending to turn the housing are sufficient to overcome these overall frictional forces as well as the torsional restraint provided by the elastomeric sleeve 29. Thus, with respect to sudden twisting movements of the drill string 11 which impose commensurate inertial forces on the instrumentation housing 22, the housing will be held against turning in relation to the tool body 23 until the frictional forces developed by the shockdampening means 30 are overcome.

Accordingly, since electronic components are typically rated to withstand accelerational forces at least in the order of ten times the force of gravity, it is ordinarily preferredto design the one or more shock-dampening means 30 for frictionally restraining twisting of the instrumentation housing 22 until these torsional forces exceed this selected level. Those skilled in the art will recognize, of course, that selection of this design criteria will mean that the overall frictional force developed by the one or more clamping members, as at 31, at a given design depth would be equal to then times the weight of the housing 22. Thus, with a given coefficient of friction, the total cross-sectional areas of the one or more piston members 34 as well as the design of the camming surfaces 36 and 37 can be readily selected for providing this desired clamping force at a given pressure in the flow passage 27. I

As previously mentioned, these suddenly-imposed accelerational or impact forces are not the only factor to be considered in protecting the instrumentation housing 22. In particular, those skilled in the art will realize that there will also be sustained low-order vibrations acting on the instrumentation housing 22 which, if allowed to go unchecked, can similarly damage the data-transmitting means 14. Accordingly, it is of equal importance in the practice of the present invention to understand that the new and improved shock-dampening means 30 are also uniquely effective for protecting the instrumentation housing 22 from torsional vibrations which themselves are of lesser magnitude than the impact or accelerational forces discussed above. Since those skilled in the art can readily understand the principles of the present invention without a full development of the applicable underlying theory of vibrational analysis involved here, it is believed sufficient to simply state that it can be demonstrated that the most-destructive condition which the instrumentation housing 22 can be subjected to is where the housing is unrestrained and the torsional vibrations acting thereon are at the natural vibrational frequency of the elastomeric sleeve 29 carrying the housing. Under this resonant condition, the instrumentation housing 22 would be moved or turned through an are far greater than the oscillatory are through which the tool body 23 is being twisted as a result of these torsional vibrations.

Under typical drilling conditions, it can, of course, be demonstrated that the frequency of these torsional vibrations is ordinarily somewhat less than the aforementioned natural frequency. Nevertheless, this does not mean that these low-frequency vibrations are of no consequence since, if they are unchecked, the housing 22 can be easily damaged. The frictional forces supplied by the new and improved shock-dampening means 30 of the present invention can, however, be shown as providing significant dampening effects which are directly related to the magnitude of the outward displacement forces imposed on the several clamping members 31. Thus, when the well tool 10 is operating in the borehole 13, the degree of frictional dampening serving to protect the instrumentation housing 22 against typical torsional vibrations will be directly related to the fluid pressure in the passage 27.

It will also be recognized that the instrumentation housing 22 must also be effectively isolated from transverse shocks or impacts. Accordingly, as best seen in FIG. 2, the shock-dampening means 30 further include an elastomeric sleeve 38 which is bonded between the hub 39 of the centralizer 25 and the adjacent portion of the housing 22. The thickness of the sleeve 38 will, of course, be determined by the overall space available for a given size of the tool body 23 and the housing 22. In any case, even a relatively-thin sleeve, as at 38, will ordinarily serve to effectively protect the instrumentation housing 22 from severe lateral or transverselydirected impacts on the tool body 23.

Accordingly, it will be appreciated that the new and improved shock-dampening means of the present invention are cooperatively arranged for protecting delicate downhole instruments installed in a drill string from torsional shocks and vibrations as well as lateral shocks which are typically encountered during drilling operations. By supporting the instrumentation housing in one or more centralizers having outwardly-biased clamping members which are only frictionally engaged with the internal wall of the drill string, the instrumentation housing is capable of turning in relation to the drill string whenever the housing is subjected to extreme torsional or rotative a ccelerational forces of a selected threshold magnitude for protecting the instruments. On the other hand, the frictional restraint provided by the clamping members against the drill string wall will be effective for effectively dampening any torsional vibrations on the housing which are commonly developed during typical drilling operations. Moreover, in keeping with the objects of the present invention, the utilization of pressure-actuated clamping members with the new and improved shock-dampening means disclosed herein is particularly useful in facilitating the installation and removal of the instrumentation from the drill string at the surface.

While only a particular embodiment of the present invention has been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects; and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

1. Well bore instrumentation apparatus comprising:

an elongated outer body adapted for suspension in a well bore and having a longitudinal passage arranged therein;

an elongated inner body adapted for reception within said longitudinal passage and having instrumentation means mounted thereon; and

shock-isolating means for operatively restraining said inner body and said instrumentation means from movement by shock forces imposed on said outer body and including clamping means cooperatively arranged on one of said bodies and adapted for lateral movement into frictional engagement with the other of said bodies, and actuating means cooperatively associated with said clamping means and arranged for moving said clamping means into frictional engagement with said other body in response to well bore pressures.

2. The well bore apparatus of claim 1 wherein said one body is said inner body and said shock-isolating means further include:

a resilient sleeve operatively supporting said clamping means on said inner body and adapted for at least attentuating the transmission of shock forces and vibrations from said outer body through said clamping means to said inner body.

3. The well bore instrumentation apparatus of claim 1 wherein said shock-isolating means further include:

means yieldably coupling said clamping means to said one body for at least dampening shock forces and vibrations transmitted from said outer body to said inner body While said clamping means are frictionally engaged with said other body.

4. The well. bore instrumentation apparatus of claim 2 wherein said one body is said inner body.

5. The well bore apparatus of claim 1 wherein said clamping means include at least one laterally-extendible clamping member movably mounted on said one body; and said actuating means include at least one pressure-responsive piston member cooperatively arranged on said one body for movement to an operating position in response to increased well bore pressures, and cam means cooperatively arranged between said piston member and said clamping member for extending said clamping member into frictional engagement with said other body upon movement of said piston member to its said operating position.

6. The well bore apparatus of claim 5 wherein said piston member is cooperatively sized for extending said clamping member against said other body with a predetermined force at a selected well bore pressure.

7. Well bore instrumentation apparatus comprising:

a tubular body arranged for connection in a drill string adapted for suspension in a well bore;

an enclosed housing carrying instrumentation means therein and adapted for mounting within the internal bore of said tubular body to define an annular flow passage therein for conducting pressured drilling fluids flowing through said tubular body; and

8 shock-dampening means cooperatively arranged on said housing and including normally-retracted clamping means movably carried on said housing, pressure-responsive actuating means on said housing and cooperatively arranged for movement to a selected operating position in response to an increased fluid pressure in said flow passage, and cam means' cooperatively arranged between said clamping means and actuating means for moving said clamping means to an extended position in frictional engagement with at least one wall portion of said internal bore for at least frictionally restraining said housing from turning in relation to said tubular body so long as there is an increased fluid pressure in said flow passage. 8. The well bore instrumentation apparatus of claim 7 wherein said shock-dampening means further include:

resilient shock-attenuating means yieldably supporting said housing within said tubular body and adapted for at least attenuating laterally-directed shocks transmitted from said tubular body to said' housing. 9. Well bore instrumentation apparatus comprising: a tubular body arranged for coupling in a rotatable drill string adapted for suspension in a well bore; an elongated instrumentation housing enclosing instrumentation means therein and concentrically disposed within the internal bore of said tubular; body for defining an annular flow passge'therein to conduct pressured drilling fluids flowing through said tubular body; v first shock-dampening means cooperatively arranged between one portion of said instrumentation housing and said tubular body for'yieldably supporting said instrumentation housing therein and at least partially isolating said instrumentation housing from lateral and torsional forces and vibrations acting on said tubular body; and second shock-dampening means cooperatively arranged between another portion of said instrumentation housing and said tubular body and operable only in response to an increased fluid pressure in said flow passage for frictionally anchoring said instrumentation housing to" said tubular body to restrain said instrumentation' housing from turning in relation to said tubularbody in response to torsional forces and vibrations acting on said tubular body. I 10. The well bore instrumentation apparatus of claim 9 wherein said second shock-dampening means are disposed below said first shock-dampening means.

11. The well bore instrumentation apparatus of claim 9 wherein said second shock-dampening means include:

an annular body disposed around said other portion of said instrumentation housing-means resiliently coupling said annular body to said other portion of said instrumentation housing for further isolating said instrumentation housing from lateral and torsional forces and vibrations acting on said-tubular body, at 'least one clamping member movably mounted on said annular body for lateral movement relative thereto between a retracted position and an extended position where an outward portion of, said clamping member is engaged with an adjacent wall portion of said tubular body, at least one piston actuator cooperatively arranged on said cent wall portion of said tubular body, and pressure-responsive actuating means cooperatively arranged for extending said clamping member into frictional engagement with said adjacent wall portion with an anchoring force that is proportionally related to the fluid pressure in said flow passage. 13. The well bore instrumentation apparatus of claim 11 wherein said second shock-dampening means further include:

means resiliently coupling said clamping member to said other portion of said instrumentation housing 12. The well bore instrumentation apparatus of claim I 9 wherein said second shock-dampening means include:

at least one normally-retracted clamping member cooperatively mounted on said other portion of said instrumentation housing and adapted for extension laterally into frictional engagement with an adjafor further isolating said instrumentation housing from lateral and torsional forces and vibrations acting on said tubular body. 

1. Well bore instrumentation apparatus comprising: an elongated outer body adapted for suspension in a well bore and having a longitudinal passage arranged therein; an elongated inner body adapted for reception within said longitudinal passage and having instrumentation means mounted thereon; and shock-isolAting means for operatively restraining said inner body and said instrumentation means from movement by shock forces imposed on said outer body and including clamping means cooperatively arranged on one of said bodies and adapted for lateral movement into frictional engagement with the other of said bodies, and actuating means cooperatively associated with said clamping means and arranged for moving said clamping means into frictional engagement with said other body in response to well bore pressures.
 2. The well bore apparatus of claim 1 wherein said one body is said inner body and said shock-isolating means further include: a resilient sleeve operatively supporting said clamping means on said inner body and adapted for at least attentuating the transmission of shock forces and vibrations from said outer body through said clamping means to said inner body.
 3. The well bore instrumentation apparatus of claim 1 wherein said shock-isolating means further include: means yieldably coupling said clamping means to said one body for at least dampening shock forces and vibrations transmitted from said outer body to said inner body while said clamping means are frictionally engaged with said other body.
 4. The well bore instrumentation apparatus of claim 2 wherein said one body is said inner body.
 5. The well bore apparatus of claim 1 wherein said clamping means include at least one laterally-extendible clamping member movably mounted on said one body; and said actuating means include at least one pressure-responsive piston member cooperatively arranged on said one body for movement to an operating position in response to increased well bore pressures, and cam means cooperatively arranged between said piston member and said clamping member for extending said clamping member into frictional engagement with said other body upon movement of said piston member to its said operating position.
 6. The well bore apparatus of claim 5 wherein said piston member is cooperatively sized for extending said clamping member against said other body with a predetermined force at a selected well bore pressure.
 7. Well bore instrumentation apparatus comprising: a tubular body arranged for connection in a drill string adapted for suspension in a well bore; an enclosed housing carrying instrumentation means therein and adapted for mounting within the internal bore of said tubular body to define an annular flow passage therein for conducting pressured drilling fluids flowing through said tubular body; and shock-dampening means cooperatively arranged on said housing and including normally-retracted clamping means movably carried on said housing, pressure-responsive actuating means on said housing and cooperatively arranged for movement to a selected operating position in response to an increased fluid pressure in said flow passage, and cam means cooperatively arranged between said clamping means and actuating means for moving said clamping means to an extended position in frictional engagement with at least one wall portion of said internal bore for at least frictionally restraining said housing from turning in relation to said tubular body so long as there is an increased fluid pressure in said flow passage.
 8. The well bore instrumentation apparatus of claim 7 wherein said shock-dampening means further include: resilient shock-attenuating means yieldably supporting said housing within said tubular body and adapted for at least attenuating laterally-directed shocks transmitted from said tubular body to said housing.
 9. Well bore instrumentation apparatus comprising: a tubular body arranged for coupling in a rotatable drill string adapted for suspension in a well bore; an elongated instrumentation housing enclosing instrumentation means therein and concentrically disposed within the internal bore of said tubular body for defining an annular flow passge therein to conduct pressured drilling fluids flowing through said tubular body; first shOck-dampening means cooperatively arranged between one portion of said instrumentation housing and said tubular body for yieldably supporting said instrumentation housing therein and at least partially isolating said instrumentation housing from lateral and torsional forces and vibrations acting on said tubular body; and second shock-dampening means cooperatively arranged between another portion of said instrumentation housing and said tubular body and operable only in response to an increased fluid pressure in said flow passage for frictionally anchoring said instrumentation housing to said tubular body to restrain said instrumentation housing from turning in relation to said tubular body in response to torsional forces and vibrations acting on said tubular body.
 10. The well bore instrumentation apparatus of claim 9 wherein said second shock-dampening means are disposed below said first shock-dampening means.
 11. The well bore instrumentation apparatus of claim 9 wherein said second shock-dampening means include: an annular body disposed around said other portion of said instrumentation housing, means resiliently coupling said annular body to said other portion of said instrumentation housing for further isolating said instrumentation housing from lateral and torsional forces and vibrations acting on said tubular body, at least one clamping member movably mounted on said annular body for lateral movement relative thereto between a retracted position and an extended position where an outward portion of said clamping member is engaged with an adjacent wall portion of said tubular body, at least one piston actuator cooperatively arranged on said annular body for movement to an operating position in response to the fluid pressure in said flow passage, and cam surfaces cooperatively arranged on said piston actuator and an inward portion of said clamping member for moving said clamping member to its said extended position whenever said piston actuator is moved to its said operating position.
 12. The well bore instrumentation apparatus of claim 9 wherein said second shock-dampening means include: at least one normally-retracted clamping member cooperatively mounted on said other portion of said instrumentation housing and adapted for extension laterally into frictional engagement with an adjacent wall portion of said tubular body, and pressure-responsive actuating means cooperatively arranged for extending said clamping member into frictional engagement with said adjacent wall portion with an anchoring force that is proportionally related to the fluid pressure in said flow passage.
 13. The well bore instrumentation apparatus of claim 11 wherein said second shock-dampening means further include: means resiliently coupling said clamping member to said other portion of said instrumentation housing for further isolating said instrumentation housing from lateral and torsional forces and vibrations acting on said tubular body. 